Shock absorber for vehicles



. Jan. l, 1929. 1,697,247

R. P. LANSINGI siocx ABsoRBER' FOR 'VEHICLES original Filed oct. le,` 1924 INVNTOR 7.3L

Patented Jan. 1, 1929.

UNITED STATES RAYMOND P. LANSING, OF MONTCLAIR, NEW JERSEY.

SHOCK ABSORBER FOR VEHICLES.

Application filed October 16, 1.924, Serial No. 743,924. Renevved March 28 1928.y

My invention relates to shock absorbers, or appliances for controlling the action of vehicle springs.

The general object of the invention is to provide an appliance of the frictionV type which is strong, durable and of simple construction, and therefore may be produced at a moderate cost.

A more particular object is to provide an appliance Which includes relatively revoluble structures, a relatively large number of friction elements or surfaces operative between these structures in order to give a very substantial friction effect u' ith a relatively nro-lerate pressure applied to the surfaces, yieldable means or .a spring, and inclined elements or screw threads cio-operating With the vyieldable means to produce or control the frictionpressure, which preferably differs in the different directions of relative movement of the revoluble structures.

A further object is 'to provide an appliance including some or all of the above mentioned fea-tures nand in` which single yieldable element or spring provides all necessary friction pressure, in connection With a suitable plurality of friction members or discs.

A further object is to provide avfriction shock absorber including a tight enclosure which effectively retains an oil or grease serving as a lubricant and a noise reducingor preventing medium, and also excludes dirt and Water; and preferably the appliance is so designed that there is only a single external or exposed joint or surface of moving contact, the moving surfaces at this point being held. tightly in engagement to provide an effective grease, dirt and water-proof seal.

As embodied in preferred physical forms, the invention is similar in some respects to the structures disclosed in other applications of Charles Marcus, Harold D. Church and myself, but dil'ers from such structures 1n important respects, these similarities and differmices being sufficiently pointed .out hereafter.

The accompanying drawing shows one exeniplifying structure embodying the invention. After considering this example, skilled persons will understand that many variations may be made within the principles of the invention and I contemplate the employment of any structures that are properly Within the scope of the appended claims.

Fig. l is a side elevation of a shock absorber or vehicle spring controller embodying the invention in .one form.

Fig. 2 is a longitudinal, horizontal section.`

oscillation .in relation to the main or base.

plate. These tivo principal parts of the structure may therefore be conveniently designated, especially in some of the claims, as "relatively-revoluble members or structures, or the composite structure 4 may be designated asa revoluble or oscillatory structure in `distinction from thebase. olatel and its connected parte, Whichis usua ly relatively stationary since it is most vconveniently rigidly connected to a chassis frame, as stated above. l

The base plate is formed with a short sleeve '5, and a spindle G projects from sleeve.

Usually thev spindle, formanufacturing convenience, is made kseparately and passes through thesleeve and has aheadfiitting in av counter-bore 8l of the basepla'tef. Longitudinal corrugations Qinayk beprovided on 4the spindle and in the sl" eeve,' to prevent `spindle rotation, although there is n.0 considerable force tending to causel the spindle to revolve. c

A revoluble structure et is preferably made in the form of 'a tight enclosure or housing and inthe present specific example it includes the following parts: An inner member or plate l() has Va central aperture 1K1 embracing sleeve 5 with a bearing fit. Plate I0V hasv a flat surfacel adjacentV the sleeve engaging the flat' outer face of a flat annular bearing ring` 13 located in an annular recess ,in the outer faceV of base plate 1. ring mayin some cases be ot' fibre, but is, preferably of a suitable metal such as bronze, toprovide a suitable thrust bearing for the surface 1'2 of plate 1.0, which is usually of'steel. A. Washer ll offelt or other suitable compr 'blematerial isA located in a recess'inthe outer" face no g of the base plate surrounding'ring 13. The outer face of the washer engages the inner surface of plate 10 and excludes dirt and moisture from the thrust bearing surface and also tends to retain any slight amount of grease or other lubricant that may escape by slow leakage between plate 1() and ring 13.

Plate 10 has a shallow cylindrical extension 15 terminatingin the flat flange 16. A plate 17 is formed with a hub portion 18 in the form of an annulus, lying against flange 16 with an interposed thin gasket 19. Plate 17 is also formed with an extension or lever arm 20, the end of which is provided with a ball-end fitting 21. By means of a suitable link this fitting is connected to the other relatively movable vehicle member such as the axle. rllhe lever arm may be made of any suitable or usual length. In the present specific example, the arm is much shorter than is usual in shock absorbers of the friction type. lilith an arm of this approximate length the device is well adapted for use at the front end of a motor vehicle where the axle movement is relatively small. By suitable design or adjustment ofthe friction elements, yieldable inea-ns or spring, etc., a longer lever arm may be provided and practically the same or any reasonable or desirable friction effect may be obtained in connection with such a long arm, and the appliance is then more suitable for use at the rear end of the vehicle where the axle movement is usually greater, but higher friction values have to be provided onV account vof the greater lever effect of the long arm. Y

An annulus or fiat ring 22 overlies the annular hub portion 18 of the lever arm, with an interposed gasket 23. This ring has an inturned cylindrical flange cut or otherwise arranged to provide spaced lugs 24. A suitable plurality of friction discs 25 are provided, with peripheral teeth or lugs interlitting with lugs 24. The plates thus have the necessary slight axial movement and are connected to revolve with the rotary structure 4L, and are therefore conveniently designated in some instances as rotor-connected plates7 or discs. T he disc 2i?l which is the innermost of the rotor-connected discs, lies directly against a face of plate 10 and desirably, this disc is thicker than the others so that its peripheral lugs may have positive Contact with the ends of lugs'2el. This disc 25" takes rthe wear, due to frictional contact with the innermost one of the other set of discs referred to just below, so that after longservice, if this wear is appreciable, it may be compensated for by renewal of disc 252 Otherwise, this disc could be omitted and an adjacent surface of plate 10 would then cooperate with the innermost one of the other y set of discs.

An outer housing member 28, which may conveniently be of pressed sheeet metal, has

a peripheral flange 29 over-lying ring 22, with an interposed gasket 30. Desirably, the outer face of the housing member 28 is apertured and the aperture is covered by a plate 31 removably secured by screws 32. iin aperture 33 is provided in the housing member 28 for the supply of oil or other lubricant, and this aperture is closed b y a screw plug Sil; otherwise any known or suitable lubricating nipple may be inserted in the aperture to provide for the easy connection of any known or suitable greasegun or similar appliance by which the interior of the rotary structure may he filled with oil or grease.

A nut or shifter is arranged for axial movement on spindle 6. rlhe inward end of this shifter has a lug 11 co-operating with lugs Ll2 on the outer end of sleeve 5, to prevent rotation of the shifter and permit axial movement. The inner portion of the shifter also has a flange all, the inner face of which at times engages a spacing ring or washer interposed between the flange and plate 10 to limit inward movement of the shifter. In some cases this spacer could be omitted and inward movement of the shifter would then be limited by engagement with the outer ends of sleeve lugs 42; but usually the spacing ring;l is provided since it may readily be made of definite thickness to provide for proper location of the shifter when in inward position. Y

@n the outer cylindrical face of the shifter are one or more screw threads lo of fairly steep pitch. This pitch is variable within considerable limits, and depends on other factors, such as maximum spring pressure and the desired resultant friction pressure in one 4direction of movement of arm 20.

A plate 50, which may be conveniently identified a pressure plate, is provided with a central aperture having threads 51 engaging threads 16. A. moderate but definite clearance, as at 42, is provided between the inner face of plate and the outer face of `flange s--l for a purpose described below.

Spaced lugs protect inward from plate 50 and a second set of friction discs 60 is provided, having their inner periph ries formed with teeth or lugs fitting between the plato lugs so that the discs are compelled to rotate with the plate but may move moderately iu axial directions.

A spring abutment in tbc forni of a washer y or nut 35 is :uljustably screwed on the outer end portion` 66 of spindle 6, which may be of reduced diameter. The spring abutment is.' secured in adjusted position by a lock nut G7. Yieldable pressure means, represented in this example by a helical. spring TO of flat section and of substantial strength or pressure value, is properly compressed betweenl the abutment and plate 50. The inward end of the 4spring may, in some cases, engage directly with the plate, but in the present Sli specific designa dished washer is provided between the springand' the plate, and so arrangedv that thespring bears against the. fiat portion of the Washer, while the shallow peripheral flange vof the washer engages against the outer face of plate 50, leaving a clearance for longitudinal movement of the nut, this clearance beingsomewhat greater than the clearance at 42, so that the outer end of the nut will not engage the washer.

The parts of the rotor or housing),v structure may be secured together in any suitable way. For convenience in assembling' and disniounting the device, however, the hub portion 18 of lever 2O is secured to flange 16' of the inner rotor member l0 by screwsSO, which have their heads'locate'd inwardly i and housing member 28 and ring are secured tothe annular hub 18 by screws 81, which have their heads arranged outwardly. In this way the musing meiner 28 may be easily removed by removing' screws 80' to .e'iv' access to' the nut or shifter, plate 50 and the friction' di"I s, without disturbing screws or separe lever armQO, or its hub i8, 'from plate l0: and at the same time, Vif desired, the ring' 29 and any or all of the friction discs may he removed for cleaning` or replacement.

rllhe detachable cover plate 3l gives convenient access to spring` abutment 65 to permit adjustment thereof without dismounting any other parts of the structure.

The appliance may be arranged to provide the greatet resistance to either vehicle spring,l

lon or recoil. It is usually considcompre ered advisable to apply the greatest resistance to the recoil movement of the vehicle spring axle, and the appliance will therefore be described asini-ranged for operati-on in that manner. The'operation when arranged to apply greatest resistanceto vehicle spring, compression. will be easily understood vby reading the operative description with suitable changes in words which' indicate positions or diri lons of movement.

The screw threads on the nutI or shifter it) and in plate- 50, have a right-hand lead, Then the vehicle is running' over approximately smooth roads, the slight movement of the axle in ,relation to the chassis frame, proi'luces .a slight oscillating; or vibratory movement of the lever arm Q0. In this movenlent there is no, or'no substazmal resist :nice to the vehicle spring; actirm. rlhe rotary structure revolves about spindle sleeve 5 carrying with it by the frictional Contact of the discs 25 and 60, plate 50, whose screw threads 5l act upon shifter threads 46 and move the shifter' longitudinally without any effect upon spring pressure or i .iction resistance so long as the angle of free movement corresponding to smooth road conditions is within the range represented by the clearance at between the nut flangev le and the inner face of plate 50; In other words, -the nut may move out to and; fro al distance represented by this clearance wit-hout `changine,` the spring pressure or friction effectv ofthe shock absorber'. During` arm movement within this range, which may be described-as a free range7 or period7 of movement; the only friction eii'ect is that produced at the contacting surfaces of plate l0 and bearing rinfr 13; but this friction may be considered and is in fact in som'ejcasesfnegligible, since, as previously stated, the ring may be constructed of bronze, which has a very small coefficient of friction when in' Contact with plate l0 which is usual-ly of steel, and moreover the bea-ring surfaces are ofismallA average radi-us. Therefore, While plate l'Oii's always urged into firm Contact with the outer surface of ring 13 by the 'pressure of spring Qa'cting thro ugh washer 75,plate 5() and the friction discs, the friction'elieet at thisv surface small or neoligible, and the vehicle sprii s' have practically free play onl compara, vely smooth surfaces. i

Wvhe'n the vehicle wheel' strikes an obstruction sufficiently high abrupt to cause the axle to move up considerably in relation to the chassis frame, lever 2O is moved countercloclrwise as in Fig. l, or thelball end moves away from t ie eye of thev observer in Fig. 2.

'lf shifter el() has previously been in an outward position, it is iirst moved inward by the action of the screw threads until its flange engages spacer 45.1 Further movement of arm 2Q thereupon, by the frictional contact of the dises 25 rand 60', causes `plate 50 to rotate slightly further along with the discs and the entire rotary structure, while nut l0 remains stationar b 1 reason of the eno'aeenient of i D C lugs ll with sleeve lugs-d2. AThe reaction of the screw threads causes plate 501 to move slight-ly outward or in other words, the plate rides up on the screw threads and the spring` pressure exerted' through the plate upon the friction discs is relieved to' a substantial degrec, and thereupon rslippage commences between the contacting surfaces of all the friction discs of the two sets, this friction representing less than the normal compression value of spring'TO, the reduction in pressure being proportional to the aixal n'ioveuwft of plate 5() `which takes a substantial part of the spring thrust and. conveys the remaii'ider 'of the sprin pressure to the friction dises; The resultant pressure on the. friction discs may evidently be varied considerably by properly regulating the pitch of the screw threads and the normal spring` pressure. In a particular example, the resultant spring pressure may be such thatthe frictional resistance to the arm movement as measured in pounds at the ball fitting 2 1, Will be approximately 20% (more or less) of the resist-snee to arm move-` ment in thel other or recoil direction. It will be evident that this resistance, which is built up quickly and practically immediately after lll() passing through the free range at the beginning or' the stated axle movement, is maintained to the end ot that movement.

`In the ensuing` recoil movement wherein the axle moves away from the chassis trame, the entire rotary structure el including plate 5() and the triction discs at first move together by the friction contact oi' the discs. The screw thread reaction which tended to move plate outward is first relieved and then plate screuv threads 51 act on the shifter threads flo and move the shilter outward until the clearance at is taken up. luring this movement there is practically no i' 'iction resistance, and this small angle oit 'tree movement at the beginning ot the recoil stroke is desirable because it definitely prevents any complete or partial tendency toward a. loching action or toward the creation otany considerable or excessive resistance, `which 'would tend to prematurely clic-cl; the the bcginning oil recoil. TWhen the clearance Ll2 taken up by flange -lsl strikingthe inner tace 0f plate 50, shifter Ll() can move no 'farther outward along the spindle; plate. 50 is locked against further rotation in the recoil direction (by reason ot the iirevoluble connection of shifter l0 to sleeve 5) g slippage therefore commences at all the friction suifaces, the friction resistance so produced being equal to the full pressure value oiE spring and this condition continues to the end oit the recoil movement. `W ith a spring` ot reasonable dimensions and adjusted for proper pressure value, and with a substantial number of triction discs, a very substantial friction resistance is thus opposed to recoil vrobes of arm 20, this resistance being unsually very much greater than the resi tance atl'orded to the vehicle spring compression movements.

rl`he structure described as a physical eml'iodiment ot the present inrei'xtion is .similar in important respects, both as to structure an d operation, to the structures disclosed in prior applications ot harles li/larcus, Ser. No, 600,082, tiled November 10, 1922, and Harold D. Church, Ser. No. 19,15?, tiled February 15, 1923, and Ser. No. (319,158, tiled February 15, 1923` o'lf which the last named application to Harold l). Church, Ser. llo. 619,1 may he taken as a tyiiiical example. these previous structures the principle oi combined spri pressure and inclined surfaces sci-civ {lirez-ids actingA on a pres-:ure inv het is cniployed to produce a delinite b i` moderato friction resistance to movcmci arm in one direction andv a v f mg. u..

rcction, with a small a tively tree movement f the vehicle is running on compa siuoot-h roads. ln the applications inentioned, however, toe pressure member or plate is directly connected by screwv tlweaos with a fixed spindle, and the maximum pressure in direction ot arm movement. Such an el'lcct is prevented in the earlier application by making` the thread pitch angle sufliciently steep to prevent locking` or excessive pressure.

fin the present invention, as distinguished from the previous applications, the maximum pressure ellect is dependent solely upon spring;` pressure, since when lever arm 2O moves in the direction correspending` to the greatest friction resistance, plate 50 is detinitely locked by contact n' ith the shifter tlange -l and the pressure exerted upon the 'friction d sc.: is then due only to the thrust of spring 7l), so that with any reasonable or practicable spring dimensions and number ot friction discs any positive lockingv ot lever arm 2O is impossible, regardless of the pitch angle ot the screw threads.

.lhe exemplit'ying struct-ure here shown is also similar in many respects to prior applications oit' Harold D. Church, Ser. No. 619,159, tiled Feb. 15, 1923, and my prior applications, Ser. llo. 12,532 and 713,533, filed May 159 19241;, and other oi' my applications temporarily idontitied as Cases 7, 8 and 9; and it is especially similar to the structures shown in Case 9. The present structure is in tact, cept for minor features practically identical with the structure shown in Fig'. 6 ot said 'Case 9, which isv included in that application because of its similarity to the other structures there shown, but not particularly claimed in that-appliance because it represents a species distinct from the other species disclosed. rllhe present application therefore is, except for minor differences, a division or continuation in part ot said application, Case 9, for the purpose of claiming` the features ot the invention as shoivn in Fig. 6 of Case 9 and in the present application.

ln all of the shock absorber structures shown in the applications just above identilied, except ll l ot Case 9, to which further reference nill not be made because itis inv general. priuftically .identical with the prescntllisclosure, tivo vieldable pressure devices which are spr-.c-itically springs, are en'iployed. and although it is s iciently apparent. by the disclosures ot said airiplications that in seine cases a single spring` may be employed, they do not shou r describe specifically a structure embodying` features common to said prior structures and the present structure, but arranged 'for satisfactory operation With only one yieldable pressure element or spring. lt has been found by study and experiment that wherey a suitable number of friction sur:t'aces lll) are provided, for instance, by the en'rploy- Inent of twov sets of interfitting friction plates 0r discs, which may be made' sufficiently thin so that a large number of plates may be ar-y ranged in a small space, su cient friction resista-nce can be provided with quite moderate spring pressure, and in fact a single spring of moderate dimensions and pressure value may be employed, as here disclosed.

The housing of the rotary structure 4: is usually partly or entirely filled with a suitable liquid medium such as' a. heavy oilv or grease, Such liquids, 1 or semi-liquids, of course, act as lubricants, and in the structure shown, in which there is no Adefinite partition in the rotary structure, the lubricant has access to all the parts including the friction discs, and the design is suoli that a; sufficient number of discs may be provided to give the desired friction value with lubricated sur faces. Lubrication ofall the parts materially reduces wear, especially on disc surfaces and the screw threads. lVhen lubrication only is in view a smaller amount of lubricant may be provided; but a liquid medium` such as a lubricant also has an important noise-preventing or reducing effect, and for that purpose a relatively large amount of the liquid or semi-liquid medium is introduced into the casing, sufficient to approximately fill it, or at least to come upto the level of the shifter or considerably above the upper edgeo-f the shifter when the appliance is arrangedwith the spindle horizontal, as in Fig. 1. From this point of view the liquid agent in the casing is to be considered as a noise-reducing or preventing medium, without necessary regard to its` lubricating qualities, and in fact the liquid need not have any substantialflubrr eating value. lfVhen a liquid-or approximately-liquid medium is provided in the manner and for the purpose described, it has access to both ends of the nut or shifter 40, and acts as a yieldable cushioning medium between the ends of the nut and Washer Tand spacer 45 and the end of sleeve 5 and the sleeve 'lugs 42, and materially reduces or entirely prevents any noisev which would otherwise be causedby the contact of the shifter with other parts as it moves axially to and fro. In the absence of any lubricant or noise preventing medium this axle movement of the shifter with abrupt contact with other parts at eitherend of its stroke, causes considerable noise or rattle, which is objectionable in some cases.

I claim:

l. A vehicle spring controlling appliance comprising relatively revoluble structures, friction elements intermediate the structures, a single spring' for producing friction pressure, a revoluble pressure member intermediate the spring and the friction elements, and controlling means acting to lock the pressure member against rotation in one direction of movement, whereupon the normal pressure `of the spring' isv applied to thev friction elements, and also' acting to' free the pressure memberlfo'r rotation` in the other direction and at the sameftimeto urge the p v'essure member to resist the spring pressure and reduce the' effective pressure on the frici elements co-operatin'g with the pressure mem` ber to lo'clr it inv one direction of movement and to urge it against the spring pressuleto reduce 'the frictional effect in the other direction of movement. Y. i l. A vehicle spring controlling appliance comprising relatively revoluble structures, a plurality of friction discs'intermediate'lthe structures, a single spring for producing friction pressure, a revoluble pressure plate in'- tcrmediate the springand the friction' elements, and an irrevoluble shifter having screw-ccnnectionjwith the'pressure plate and actingto lo'cli'the plate against rotation in one direction of movement", whereupon .then'or mal pressure ofthe spring is applied through the plate to the diss,'and also acting to free the ,pressure Eplatezfor rotation in the other direction and `at. the same time to urge the plate to resistA the spring pressure aridjreduce the effective pressure on the frictiondiscs.

il vehicle spring controlling;appliance ccn'iprising'* a base plate adapted for kconnection to a vehicle frame member, a revoluble structure moiiiited for rotation: in respect'to the ybase plate., a set of friction'discs iconnccted to revolve with the revoluble structure, ashifte'r, a pressure,member having screw thread connection with the shifter, a set of friction discs connected to rotate with the"y pressure member and interi-fitting with the discs of theset first mentioned, and a single pressure spring acting on the pressure member.

5. A vehicle spring controlling appliance comprising a base plate adapted for connection to a vehicle frame member, a revoluble structure mounted for rotation in respect to the base plate, a set'of friction discs connected to revolve with the revoluble structure, a shifter, a pressure member having screw thread connection with the shifter, the shifter having a locking member co-operating with the pressure member and having a substantial normal clearance therefrom.

6. A vehicle spring controlling appliance comprising a base plate adapted for connection to a vehicle frame member, a revoluble` lili() structure mounted for rotation in respect to the base plate, a set of friction discs connected to revolve with the revoluble struc-ture, a shifter, a pressure member having screw thread connection with the shifter, a set of friction discs connected to rotate with the pressure member and intertting with the discs of the set first mentioned, and a single pressure spring acting between the pressure member and an abutment secured to the base plate.

7. A vehicle spring controlling appliance comprising a base plate, a spindle extending therefrom, a revoluble structure mounted to rotate about the spindle, a rotatable pressure member, VJtwo sets of interlitting friction elements, those of one set being connected to the revoluble structure and those of the other set being connected to the pressure member, a single pressure-producing spring acting on the pressure member, and a nut arranged for axial movement on the spindle and restrained from rotation, the nut and pressure member having interiitting screw threads.

8. A vehicle spring controlling appliance comprising a base plate, a spindle extending therefrom, a revoluble structure mounted to rotate about the spindle, a rotatable pressure member, two sets of interfitting friction elements, those of one set being connected to the revoluble structure and those of the other set being connected to the pressure member, a single pressure-producing spring acting on the pressure member, and a nut arranged for axial movement on the spindle and restrained from rotation, the nut and pressure member having interiitting screw threads, the nut also having means co-operating ,with the pressure member to lock the latter against rotation in one direction after limited free travel of the nut.

9. A vehicle spring controlling appliance comprising a base plate having a spindle eX- tending centrally therefrom and a thrust bearing surface surrounding the spindle, a shifter mounted for axial movement about the spindle and restrained from rotation by engagement with the base plate, a revoluble structure constructed and arranged substan ti ally as an oil tight housing having an inner member revolubly mounted about the spindle, said member having a surface in contact with the thrust bearing surface of the base plate, a spacer intermediate said member and the shifter, a pressure plate having' screw thread engagement with the shifter, the shifter having a flange confronting the pressure plate with a substantial normal clearance, a single pressure spring acting between the abutment on the spindle and the pressure plate, and two sets of interfitting friction discs, those of one set being connected to rotate with a revoluble structure, and those of the other set being connected to rotate with the pressure plate.

10. A vehicle spring controlling appliance comprising a base plate having a spindle eX- tending centrally therefrom and a thrust bearing surface` surrounding the spindle, a shifter mounted for axle movement about the spindle and restrained from rotation by' engagement with the base plate, a revoluble structure constructed and arranged substantially as an oil tight housing having an inner member revolubly mounted about the spindle, said member having a surface in contact with the thrust bearing surface of the base plate, a .spacer intermediate said member and the shifter, a pressure plate having screw thread engagement with the shifter, the shifter having a iiange confronting the pressure plate with a substantial normal clearance, a single pressure spring acting between the abutment on the spindle and the pressure plate, and two sets of interlitting friction discs, those of oneset being connected to rotate with a revoluble structure, and those of the other set being connected to rota-te with the pressure plate, the revoluble structure also comprising an outer demountable housing portion having an outer aperture closed by a detachable cover plate.V

Signed at Hoboken, in the. county of Hudson and State of New Jersey, this eleventh day of October, A. D. 1924.

RAYMOND P. LANSNG. 

